The odor generated from a urinal apparatus fails to be sufficiently removed by flushing the bowl section of the urinal apparatus with water. Thus, various deodorization devices for removing the odor of a urinal apparatus have been proposed. Urine remaining in the urinal apparatus is decomposed by common bacteria to generate ammonia. This is considered to be the main source of the odor of the urinal apparatus. Specifically, urine remaining inside the trap of the urinal apparatus is decomposed by enzymes to generate ammonia ions and ammonia gas.
Under application of energy (such as heat and water flow) by urination, ammonia ions turn to ammonia gas. When a temperature difference occurs by urination, the ammonia gas is carried on an updraft and reaches the position of the user's nose. Thus, the ammonia gas generated in several seconds after urination reaches the position of the user's nose. This causes the user to feel an unpleasant odor.
As a countermeasure for removing the odor of a urinal apparatus, Japanese Patent No. 3480173 proposes a toilet stool unit with sterilizing water feed function. In this toilet stool unit, generation of the odor from ammonia and the like is suppressed by sterilizing common bacteria. However, it is difficult to completely sterilize common bacteria. In this regard, the toilet stool unit with sterilizing water feed function disclosed in Japanese Patent No. 3480173 has room for improvement.
On the other hand, Japanese Utility Model Registration No. 3081605 discloses a male urinal flushing device. In this device, the flush valve is operated with a cartridge in a hole. Then, the detergent in the cartridge partly dissolves into the flush water flowing into the cavity and flows out from sprinkling holes into the urine receptacle. However, the male urinal flushing device disclosed in Japanese Utility Model Registration No. 3081605 supplies detergent into the male urinal together with flush water when flushing the male urinal. Thus, it cannot suppress that urine remaining in the male urinal after use of the male urinal is decomposed by common bacteria to generate ammonia.
Furthermore, when flushing the bowl section of a urinal, it is necessary to remove foreign matter such as urine and hair attached to the surface of the bowl section, and to replace the seal water in the trap section. Thus, it is necessary to pass a relatively large amount of water at a relatively fast flow velocity. Accordingly, two regions are produced on the bowl section in order to suppress water splashing out of the bowl section. One region of the bowl section is supplied with water, and the other region of the bowl section is not supplied with water. Urine attached to the region of the bowl section not supplied with water remains fixed without being flushed with water supplied to the bowl section. Thus, the region of the bowl section not supplied with water acts as a source of the odor.